The preoperative accurate diagnosis is difficult in the patients with intraductal papillary mucinous neoplasm (IPMN). The aim of the present study was to elucidate the roles of systemic inflammation responses and nutritional status indexes in IPMN. High-grade dysplasia was classified as a malignant neoplasm in the study. We retrospectively reviewed 155 patients who underwent pancreatectomy. The correlation between the clinical factors and several indexes of a systemic inflammation response and nutritional status was analyzed. Among the biomarkers, prognostic nutritional index (PNI) value of malignant IPMN patients was significantly lower than that of benign IPMN patients (P = 0.023), whereas PNI was not significant predictor for malignant IPMN. The multivariate analysis showed that a PNI < 43.5 (odds ratio [OR] 16.1, 95% CI 1.88-138.5, P = 0.011) and a carbohydrate antigen (CA) 19-9 level > 22.5 U/mL (OR 6.64, 95% CI 1.73-25.6, P = 0.006) were significant independent predictors of the presence of lymph node metastasis (LNM). Our scoring system developed based on these two factors. Patients with a score of 0 had no LNM and zero disease-related death. The present study suggested the roles of PNI on the IPMN patients who undergo curative pancreatectomy.